Abstract

Food habits of jaguar and puma were studied in two regions of the Paraguayan Chaco. Biochemical analysis of 280 scats attributed 106 to jaguar and 95 to puma. Overall dietary overlap was 65 percent and they shared six of seven main prey types. For both cats 43 percent of prey items and 15 percent of prey biomass taken were mammal species <1 kg, 23 percent of items and 29 percent of the biomass were from species 1-15 kg, and 27 percent of items and 53 percent of the biomass were from larger species. Birds, reptiles, and insects made up the remainder. In a developed region no significant differences between their diets were found, while in an undeveloped area more small mammals were taken by both species, and jaguar took more large prey than puma. The potential roles of competition and of differences in habitat structure and prey availability between the two areas on these species' diets are discussed.